Beri, G. C. (1993). Marketing research (Second edition.). Tata McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Beri, G. C. Marketing Research. Second edition. New Delhi: Tata McGraw-Hill, 1993.
Lua MLA (8ú heag.)Beri, G. C. Marketing Research. Second edition. Tata McGraw-Hill, 1993.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.